Carbureter.



S. l. PRESCOTT.

' CARBURETE R.

APPLlCATlON mwozc. 1. 1914.

s l. PRESCOTT.

CARBURETER.

p APPLICATlON FILED DEC. 1. 1914. F l,1%3,22 Patented June 15, 1910.

3 SHEETSSHEET 3.

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' 6:1 5 S x g "1 sgnivng 1. rnnsoo'rr, or BROOKLYN, NEW YORK:-

CABBURETEB;

Specification ofLetters Patent.

Patented June 15, 1915.

Continuation of application Seriai N SZOJMQ, filedNovexriheri', igi. This application filed December 1,

To all whom itmay concern:

Be it known that I, I a citizen of the United States, Brooklyn, county of Kings, and

residing at State '0 New York, have invented a new and usefulo m in b et s. iWh' dl the following isa specification..

This invention relates to an mprovement in carburetors, andthis application 1821 6011- tinuation of my earlier ap'plication "Serial fuel into the air and have also included an auxiliary air Ills take for dilutingthe rich mixture formed in the Venturi tube,' In sueh devices, the ven; turi tube is of fixed diameter andform and is usuallydesigned to produce a rich mixture for engine starting and for slow running, the auxiliary air intake being relied upon to: furnishv the desired quantity and quality of mixture for high speed. YCertain carburetors heretofore knownhave -made use of a second or auxiliary fuel nozzle for supplying additional fuel when the auxiliary air intake is in operation. Certain other carbureters have made use of 'a' relatively large. intake or Venturi tube capable of supplying air enough for high speeds and provided with an internal chokedevi'ce adjustable to supply air enough forlotv speeds only. While such devices furnish a proper mixture for low and for high speeds, they do notfurnish a proper mixture for'th'e wide range of speeds 'lying between those extremes, Whena carbureter designed as indicated above, used inlconnection with an engine driving an automobile, it is operating at low efiiciencymost of the time'; most of the time the engine'is running at speeds between low and'high, in which case the carbureter cannot be properly adjusted. Various attempts have beenniade to correct this serious defect by, hand-controlled devices for admittingmore air, or more fuel, or both, as [changing conditions require; but none of these" carbureters' are efiicient .or otherwise satisfactory under all speeds.

The present invention has'for its main a rbureter which object the production of .a c

SYDNEX ,I. Pnnsoorr,

tube manta is located a e athigl el f yi for the e s-wee.

will automaticallyadjust itself to the reguirements of the full'range of'engine speeds in infinitesimal variations.

Anairintake or Venturi tube to be most eflio ent. at any given speed, should'be circular ri form, the fuel'nozzle standing concentr cally in the center of the circle to interfere as little as possible with the flow of air past .it and to evenly distribute the fuel in the; moving stream of air. Where the Venturi tube isof fixed diameter, such a device 1s most efficient at one speed only.

It isoneiof the objects of this invention to produce aiiair intake/or Venturi tube forming a passage which will retain its efficient form but whlch can nevertheless be adjusted to vary the amplitude of said passage. An another object of the invention is the production of aldevice efiecting this result automatically. i

stillanother object of the invention is the production of a device in which the desired result effected by the action of the engine itself, so that the action'of' he carburetor will 'automatically correspond with the action of the engine, supplying more air and fuel whenthe engine requires it and supplying less air and fuel when the engine requires that, and automatically varying the proportion of an to fuel in accordance with variations in the requirements of the engine under varying 'conditions' Still another object of the invention is the'production' of a device in which the fuel is sprayed into the stream of air at the most efficient poi t' and in themost efficient way at'all'speeds,'the'quantity of fuel as well as the quantity of air being automatically regulated by the on no itself.

Stillanoth'er o ject of the invention is the production of a fuel nozzle constructed to cause the fuel to be brought in contact with the stream of air in fuel an the form'of an exceedingly thin film, so that the maximum possible surface of the fuel is exposed to the action of the air.

Still another object of the-invention is the production of a nozzle of the general character just mentioned, in which the fuel is formed into an exceedingly thin hollow stream, both the interior and exterior of this the air'intake while said of fuel supply,

production'of a device in which the atomizing effect of a stream of air flowing at a higher velocity than thatof the air in the intake is utilized for the purpose of more quickly securing, and in fact, insuring, an intimate mixture of the fuel and air which will retain its homogeneous character as it passes to the engine. i

A further object of the invention isthe production of a carbureter having fewer parts, none requiring adjustment; a carbureter which is more efficient-and durable than those heretofore known and which is less expensive.

With these and other objects not specifically mentioned in view, the invention con sists in certain parts, constructions and combinations which will be hereinafter fully described and then specifically set forth in the claims hereunto appended.

In the accompanying drawings, which form a part of this specification and in which like characters of reference indicate the same or like parts, Figure 1 is a plan view of a device constructed in accordance with the invention, partly broken away; Fig. 2 is an end view of the structure shown in Fig. I; Fig. 3 is a longitudinal sectional ,elevation taken on the line 3-3 in Fig. 1;

Fig. 4 is a cross-sectional view taken on the line 4-4 in Fig. l, but illustrating an air inlet differing in form from that shown in Fig. 3; Fig. 5 is a cross-sectional View. taken, 1 v i jlt'self where a manifold is not used.- Coon the line 55 in Fig. 3; Fig. 6 is a-detail the throttle operating mechview showing 7 is a fragmentary anism in elevation; Fig.

detail view illustrating a form of nozzle dif-;--

fering from that shown in Fig. 3; andfFig. 8 is a detail sectional view illustrating a modified form of inlet holding bolt and'air nozzle adapted for use when air under pressure is to be used.

Incarrying the invention into effect, there is provided a source of air supply, a source and co-acting means for producing infinitesimal variations in supply of air and supply of fuel in accordance with infinitesimal variations either in the speed of an engine in connection with which the device is used, or in the suction established by that engine. In the best constructions, there is provided an air intake shaped and adapted to retainits form but to vary its amplitude in accordance with the varying requirements of the engine in connection with which it is to be used. In the best constructions also, this air intake is circular in form and arranged concentrically With respect to a source of fuel supply or fuel nozzle, the concentric arrangement being main tained throughout the whole range of action of the air intake. In the best constructions also. means are provided for causing the air intake to resume its normal amplitude whenever the requirements of the en'- gine with which the device is used permit it. In the best constructions also, the variable air intake cooperates with the fuel nozzle in the most eflicient way, and a throttle or similar means is provided for controlling the flow of air through saidintake. In the best constructions also there is provided means for forming fuel into a hollow stream having exceedingly thin walls, both its in terior and exterior being exposed to the ac tion of air. In the best constructions also, means are provided for conducting a stream of air to the deliveryend of the fuel nozzle where it cooperates with the fuel issuing from the fuel nozzle, the current of air flowmg at a h gher velocity than the velocity of the air lnthe intake, so thatthe fuel is thoroughly atomized and caused to form with the air in the intake a homogeneous mixture.

Many changes and variations may be made 'n the construction by means of which the invention is carriedinto'efi'ect. Moreover, certain parts of the'invention are capable of use independent of other parts, and such independent use is contemplated. The in vention is therefore not to be restricted to the details of the specific structure shown and'descr'ibed." Irrithe device selected toillustrate' the invention, 1 indicates a casting having a flange foldof anengine, or to the engine casting operating with this casting l is an air in- 'let3 having an open mouth 4 in whicha hot airpipe, not shown, may, be-inserted." A clamp? screw 5 of a well known character is provided, the function of this clamp screw '3. By an inspection of Fig. 3, it will be seen that this inlet may be swung around to the p0si,tion which happens to be the most deslrable for any particular installation. A

modified form of air inletisshown in Fig.

4 and is marked 6. This modified form of air inlet has an upturning open mouth 7 provided with the usual clamp screw 8.

he means for holding this air'inlet in position will be hereinafter described. Through theflange 2 is cored or bored a fixed tube 9 through which air flows from the inlet 3 through the flange to the manifold or engine, not shown.

Between the inlet 3 and the fixed tube 9, the casting'l is chambered at 10 and 11 to receive a pair of co-acting movable members, the function of which is to variably resist the passage of air from the inlet 3 to the fixed tube 9. These movable members are rocking members'marked l2 and 13 and may be termed intake amplifiers since their main function is to amplify the passage between the inlet 3 and the fixed tube nozzle 21 fee i which also serve The amplifier 12 is provided with 9. Each amplifier is rotatably mounted upon one of a pair of studs 14. Each of these studs has its ends reduced, the reduced ends passing through plates 15, which plates are rabbeted into the casting 1, as clearly shown in Figs. 1, 3, 4 and 5. These plates form the side walls of the chambers within which the amplifiers lie. The reduced ends of the studs 14 project beyond the plates 15, and upon the ends so projecting are threaded nuts 16 which serve to hold the plates 15 in position on to hold the studs 14 in position. gear teeth 17 which are intermeshed with gear teeth 18 formed on the amplifier 13. The main purpose of these intermeshed gear teeth is to cause the amplifiers 12 and 13 to move in synchronism. These gear teeth, however, perform another function which will be hereinafter described. The amplifier 12 is provided with a circumferential progressively expanding groove 19 semi-circular in cross section sunk below the gear teeth 17. Similarly, the amplifier 13 is provided with a circumferential progressively expanding groove 20 semi-circular in cross section sunk below the gear teeth 18. These grooves co-aet to form a passage circular in cross section, lying in the path of a stream of air passing from the inlet 3 to the fixed tube 9; and as the amplifiers 12 and 13 rock, this circular passage retains its cross-sectional form but is increased in amplitude, this action being due to the progressively expanding character of the grooves 19 and 20.

Located in the passage and concentric therewith is a source of fuel supply. or fuel nozzle 21 of well known construction. This fuel nozzle is in open communication with the fuel reservoir 22 formed in the main casting 1. The delivery end of the fuel in the air passage and consequently at the point of highest air velocity, a point substantially immovable during the movement of the amplifiers because the'centers of the arcs coincident with the bases of the semicircular grooves 19 and 20 are in a plane including the delivery end of the nozzle.

he highest possible efiiciency of the fuel nozzle is thus insured irrespective of the position of the amplifiers. Within the fuel reservoir 22 is mounted a float 23 carried on a stem 24, which at its lower end is provided with a ball valve 25 operating to control the flow of fuel into the fuel reservoir. The ball valve 25 operates within a filtering screen 26 which is held in position by means of a plug 27 This plug also serves to hold in position a connection 28 provided with an annular fuel chamber 29 and with a threaded aperture 30 into which a fuel pipe By an inspection of Fig.

may be screwed.

the casting 1, and.

lies at the point of least diameter v is limited by means of a pair of 3, it will be readily seen that this connection 28 may be swung around to any convenient position. The top of the reservoir 22 is closed by a cover 31 provided with an air vent 32 and with an aperture 33, which serves as a guide for the upper end of the stem 24 before referred to. A cap 34is provided for inclosing the upper end of the stem 24 and the aperture 33. The cover 31 is held in place by the free end of a spring 35, the opposite end of the spring being secured to the top ofthe casting 1 by means of aserew 36. A drain plug 37 of well known construction is provided and screwed intothe lowermost part of the wall of the fuel reservoir 22. Open communication between the fuel reservoir 22 and the nozzle 21 is established by a hole 38 drilled into the casting 1 from the reservoir to a chamber 39 formed in a boss 40 lying below and between the amplifiers 12 and 13. The lower end of this chamber is closed by means of a plug 41 and into this plug is threaded a cap screw 42 which holds the inlet 3 in position as adjusted.

\Vithin the fixed tube 9 is located a butterfly throttle valve 43 secured to a valve stem 44 journaled in and projecting through the walls of the tube 9. On the projecting end of the valve stem 44 is clamped in a well known manner a stop device 45 having separated horns 46. Each horn is provided with an adjusting screw 47 and retaining spring 48. These adjusting screws are adapted for contact with abutments 49 projecting from the main casting 1 before referred to. It will be noted that these abutments exist on both sides of the device. This'is for the purpose of permitting the reversal of the throttle and stop when this is desired; that is to say, the throttle may be mounted in the casting with the stop device upon either side thereof. Beyond the stop device 45 a throttle operating lever 50 is clamped in a well known manner upon the valve stem 44. This lever is so constructed that a hole may be drilled therein at any desired radiuswitlv in its limits from the axis of the valve stem 44 for establishing connection with any suit able valve operating mechanism leading from any desired direction.

The movement of the amplifiers 1.2 and 13 rods 51,

the ends of which are pocketed in suitable apertures formed in the plates 15, as clearly shown in Figs. 1 and 3. By an inspection of Fig. 3, it will be readily understood that the amplifiers 12 and 13 are weighted in such 7 manner that their centers of gravity lie below and nearer together than the studs 14 upon which they are mounted, so that in the absence of any disturbing force, gravity will bring them into and hold themat the position shown in Fig. 3, which is the position they occupy when the device is not in action.

. modate the ball 64 In the form of nozzle-illustrated in Fig. 7

the upper end of the nozzle .52 is provided with an aperture 53 nearly as large as the main bore of the gozzle. Within the nozzle 52 is located a second nozzle 54, the walls of which are concentric with the walls of the fuel nozzle 52. The nozzle 54 is provided near its upper end with a flange 55, through which one or more channels 56 are cut. The exterior of the upper end of the nozzle 54 is but slightly less than the aperture 53 of the fuel nozzle. The nozzle 54' is hollow and adapted to conduct a stream of air to the delivery end of the fuel nozzle. When this stream of air is to be induced by the suction of the engine itself, the nozzle and allied parts will be in the form shown in Fig. 7. By an inspection of Fig. 7, it will be seen that this air nozzle 54 is formed" integrally with the plug 57 screwed into the boss 40 before referred to, and it will be further seen that screwed into this plug 57, is a clamping cap screw 58 having a longitudinal hole 59 and a lateral hole 60 drilled therein for the purpose of conducting air from the interior of the inlet 3 to the interior of the nozzle 54. It will be readily understood also that the clamping cap screw'58 also performs the function of holding the air inlet 3 in adjusted position. It will be understood that by the structure just described, the fuel is formed into a hollow stream, the quantity issuing from the nozzle being controlled by the channel or channels 56 in the flange 55; and it will be further understood that the fuel issues from the fuel nozzle in the form of an exceedingly thin tubular film of exceedingly largesurface area, and that both the interior and exterior of this thin film is brought into contact with the air passing through the air nozzle 54 and the air passing through the passage between the amplifiers 12 and 13.

When air under pressure" is to be used within the hollow stream of fuel so that the V velocity of the .air within the stream of fuel will exceed the Velocity of the air through the intake passage,

nor the cap screw 58 will be used, but in place thereof a different form of clamping screw marked 61, and be substituted. This shownin Fig. 8, will clamping screw hasa longitudinal hole 62 drilled throughout its length and beyond its clamping surface is provided a threaded aperture 63 adapted for use in connection with'a suitable pipe for conducting air under pressure from any suit able source of the same. When this device is used, therernay be provided a check valve consisting of a ball 64 normally closing the upper end of the aperture 63. The upper end of the hole 62 is enlarged at 65 to accomand the upward move ment of the ball 64 islimited by means of a pin 66. The enlarged portion the plpe connected therewith.

valve lSIlOlJ necessary however, except for crankinig of the engine.

neither the cap screw. 42

65 of the hole h 62 is inopen'communication with the bore 67 of an air nozzle 68 adapted to take the place of the air nozzle illustrated in Fig. 7 The air. nozzle 68 is provided with a flange 69' nozzle within'the fuel nozzle to form a thin film of fuel and to control the flow of'said fuel. In the event of an overfiowfof fuel into the air nozzle 68 when the device is not in use, this ball flooding of the clamping cap screw 61 and I The check the purpose just described, and in many installations might be omitted with safety.

7 The operation of the den'ce illustrated in Figs. 1 to 6 inclusive is as follows, it being understood that the parts are in normal position, or that shown in Fig. 3, in which the passagebetween the members is smallest. It may be here remarked that therelative areas of the intake in normal position and of the fuel nozzle are designed for highest possible efli'cien'cyunder' the most unfavorable conditions; that is to say, in starting the engine in cold weather or in high altitudes. The throttle being open slightly to start the engine in connection with which the device is used and the engine being turned over either by hand or by mechanical means, tablished in the fixed tube 9. Air under atmospheric pressurecan only reach this fixed tube by coming. through the inlet 3 and-- passage formed between through the small the amplifiers 12 and 13 around and concentric with thefuelnozzle. The Weight of these members is suflicient, under the low suction established at this time, to prevent them from'moving; or, at least, to permit only a very'slight movement, the exact position depending entirely upon the speed of relative v tween the amplifiers as compared with the amount of fuel drawn from the fuel'nozzle. The result is a very rich. mixture, which is preciselywhat is desired at this time. As the engine picks up its cycle-of operations, operates under its own power and increases check valve 64 will prevent.

apartial vacuum is es- I In either event, a y small amount of air is drawn beits speed, the throttle still being opened only a little, the suction increases and the amplifiers l2 and 13 rock a little'more so that more air isradmitted, the only resistance to this movement being the weights of the amplifiers themselves. It may behere'. remarked that the incoming air acting upon the gear teeth 17 and 18 of t e amplifiers 12 and 13 tends to aid'this opening movement against the resistance of the amplifiers. The suction being stronger at t is time, more fuel is also'drawn from the weights of the amass? nozzle 21,- so that the volume of both air and fuel is increased, while the roportion of air to fuel is slightly decrease both of which are precisely what is needed atathis time. Then if the throttle is opened still more, the suction at once increases in the fixed tube 9 and this results in opening the passage between the amplifiers 12 and 13 still more and drawing still more fuel from the nozzle 21; but since the fuel drawn in is heavier than the air drawn in, the proportion of air to fuel increases. The effective result is a greater quantity of mixture not so rich as when starting but. still rich enough for a quick pick-up, or increased speed of the engine. This is precisely what isneeded. at

V this time. All through the wide range of nest. Thisis precisely what is wide open position,

. swung up toward each c richer mixture, which is needed at this time.

tion ceases,

the speed of the engine reduces, tion is also re ment of the amplifiers back towardnormal position in strict accordance with the variengine speeds and infinitesimal variations therein, the mixture grows thinner as speed increases until at maximum speed it is thindesired at this time. Any possible tendency'ofthe vice to produce a-mixture too thin at high speedsis prevented as follows: Asthe amplifiers move from their normal position v to 14 to positions nearer together. ing efiect of the weights upon'the'amplifiers in normal position is very little because they are then very" nearly under the supporting studs of the amplifiers;

b'ut as they are other by the movement of the amplifiers, their turning "eifor't is increased and flowing streamof air and maintain air between the amplifiers as the I fuelthrough the nozzle is retarded. n The proper mixture is thus insured. In the event of a heavy load for instance when the engine is driving an automobile and the latter is climbing a hill, and the sucneed." This results in a moveations in the suction. This further restriction of the passage results of course in a precisely what is If the engine is slowed down by a partial closure of the throttle, the amplifiers automatically assume the proper position for the resulting suction and if the throttle is entirely closed and suethe amplifiers will automatically return to their normal position or that shown in Fig.

. of air to fuel this increased turning ef-- fort operates against the action of the inand'thereby tends to. resist the rocking movement of theampli-fl fiersI When the engine is running at full; speed with the throttle wide open, this turn ing effort due to gravity. is greatest and the: efiectiveresult is to restrict the passage for the velocity of the streambf flowv 'of being placed upon quirements of which it is used; that vparts to get'out of order orout of adjustment, no adjustments being necessary;

- cooperating circumferen 3. Throughout the whole range of possible speeds, the amplifiers adjust themselves to the proper position for that speed, or rather are adjusted by the engine itself, infinitesimal variations in the supply of air and the supply of fuel and infinitesimal variations in the proportion resulting in accordance wit infinitesimal variations either in the speed of the engine or in the suction established by the engine.

The operation of the device, when the nozzle illustrated in Fig. 7 is used, is the same as the operation above described exceptin that the fuel is first formed into a hollow" stream having exceedingly thin walls, and that both the interior and exterior of these thin walls are exposed to the action of air, theresult being a quicker and more thorough mixture of the fuel and air than is possible with any nozzle from which form. This is due to the fact that the largest possible surface of the fuel is exposed to I the direct action of the The operation their centers of gravity move from positions almost under the studs.

The'rotatair.

of the device inxwhich the structure shown in Fig. 8 is substituted for the fuel nozzle shown iii-Fig. 7, is the same as the operations above described except that since the air within thethin tubular film of I fueliis conducted under pressure to the delivery end of the fuel nozzle, and at a ve- 'locity higher than the velocity of the air in- "duced' the intake by the suction of the engine in connection with which the carbureter is-used, the innerstream of air will immediately expand as soonas it issues from the air nozzleand literally blow the thin film of amt-at atoms, and in s'odoing will force these.'atomsj'radially; outward into the in- ;commg'stream of air in the fsurin'g a practically instantaneous converintake, thus inmix ture. v. It will thus sion of'the air and fuel into a homogeneous be seen that the device is absolutely automatic in action, adjustmg itself-or rather being adjusted by the engine-infinitesimally to meet the variable rethe engine in connection with there are no delicate that it contains fewer-parts than carbureters heretofore known, and consequently .is extremely simple and inexpensive in design, and more durable and more efiicient in action. What is claimed is:

1. In a carbureter, an air intake having co acting rocking members provided with ial progressively expanding grooves semi-circular in cross section said members being operative by suction established therebetween and acting thereupon to vary the amplitude of the passage between the members in accordance with suction variations.

2. In a carbureter, an air intake having intergeared co-actmg rocking members provided with cooperating circumferentlal progressively expanding grooves semi-circular in cross section said members being operative by suction established therebetween and acting thereupon to vary the amplitude of the passage between the members in accordance with suction variations.

3. In a carburetor, an air intake having co-acting rocking members provided with intermeshing geared teeth upon their peripheries and with cooperating circumferential progressively expanding grooves semicircular in cross section and sunk in said geared teeth said members being operative by suction established therebetween and acting thereupon to vary the amplitude of the passage between the members in accordance with suction variations.

4.. In a carbureter, the combination with an air intake having co-acting rocking mem bers provided with cooperating circumferential progressively expanding grooves semicircular in cross section said members being operative by suction established therebetween and acting thereupon to vary the amplitude of the passage between the members in accordance with suction variations, of a source of fuel supply located between said members.

5. In a carbureter, the combination with an air intake having co-acting rocking members provided with cooperating circumferential progressively expanding grooves semicircular in cross section said members being operative by suction established therebetween and acting thereupon to vary the amplitude of the passage between the members in accordance with suction variations, of a and concentric with the grooves thereof;

6. In a carbureter, the combination with an air intake having co-acting rocking mem bers provided with cooperating circumferential progressively expanding grooves semicircular in cross section and adapted to maintain a substantially constant point of highest air velocity in the passage between the members as the members move said members being operative by suction established therebetween and acting thereupon to vary the amplitude of the passage between the members in accordance with suction variations, of a fuel nozzle the delivery end of which is located within said passage at said point of highest air velocity.

In a carbureter, an air intake having co-acting rocking members provided with cooperating circumferential progressively expanding grooves semi-circular in cross section said members being operative in one direction by suction established therebetween and. acting thereupon to increase the amplitude of the passage between the mem bers' in accordance with suction increase said members having counter-weighted portions positioned and operative to partially counteract the effect of the suction upon the members as they approach wide open position and to return said membersto normalposition when suction ceases.

In testimony whereof, I have signed my name to this specification in the-presence of two subscribing witnesses.

SYDNEY I. PRESCOTT.

Witnesses:

F. J. RUMMLoo, ELIZABETH LOUISE RUssELn. 

